Light emitting elements, e.g., light-emitting diodes (LEDs), emit visible light when an electric current passes through it. The output from an LED can range from red (at a wavelength of approximately 700 nanometers) to blue-violet (about 400 nanometers). Some LEDs emit infrared (IR) energy (e.g., 830 nanometers or longer). The light emitting elements have a transparent package, allowing visible or IR energy to pass through to be seen by a viewer.